Sumanirole is a dopamine D2 receptor agonist that is selective for D2 over D1, D3, and D4 receptors (Kis = 9.0, >7,140, 1,940, and >2,190 nM, respectively).1 It inhibits forskolin-stimulated cAMP accumulation in CHO cells expressing human recombinant D2A receptors (EC50 = 17 nM). Sumanirole decreases plasma prolactin levels in rats when administered at doses greater than or equal to 3.1 ?mol/kg and inhibits dopamine neuron firing in the substantia nigra pars compacta (SNPC) in anesthetized rats (ED50 = 2.3 ?mol/kg). Sumanirole (≥12.5 ?mol/kg, s.c.) increases horizontal locomotor activity in a reserpinized, α-methyl-para-tyrosine (AMPT) rat model of Parkinson's disease. It also decreases time spent in the open arms of the elevated plus maze and time spent immobile in the forced swim test, indicating anxiolytic- and antidepressant-like activities, respectively, in mice with SNPC lesions when administered at a dose of 0.1 mg/kg.2 Sumanirole (≥0.1 mg/kg, s.c.) reduces premature responding, a measure of impulsivity, by rats in the 5-choice serial reaction time test (5CRTT) compared with untreated animals.3
1.McCall, R.B., Lookingland, K.J., Bédard, P.J., et al.Sumanirole, a highly dopamine D2-selective receptor agonist: In vitro and in vivo pharmacological characterization and efficacy in animal models of Parkinson's diseaseJ. Pharmacol. Exp. Ther.314(3)1248-1256(2005) 2.Carcinella, S., Drui, G., Boulet, S., et al.Implication of dopamine D3 receptor activation in the reversion of Parkinson's disease-related motivational deficitsTransl. Psychiatry4(6)e401(2014) 3.Fernando, A.B., Economidou, D., Theobald, D.E., et al.Modulation of high impulsivity and attentional performance in rats by selective direct and indirect dopaminergic and noradrenergic receptor agonistsPsychopharmacology (Berl.)219(2)341-352(2012)